China is developing "counterspace" weapons that could shoot down satellites or jam signals, a Pentagon official said Friday as the United States unveiled a 10-year strategy for security in space.

"The investment China is putting into counterspace capabilities is a matter of concern to us," deputy secretary of defense for space policy Gregory Schulte told reporters as the defense and intelligence communities released their 10-year National Security Space Strategy (NSSS).

The NSSS marks a huge shift from past practice, outlining a 10-year path for the United States to take in space to ensure it becomes "more resilient" and can defend its assets in a dramatically more crowded, competitive and challenging environment, Schulte said.

A key reason for developing the new strategy was "concern about the number of counterspace capabilities that are being developed," said Schulte.

"China is at the forefront of the development of those capabilities," he said.

China in 2007 shot down one of its own weather satellites using a medium-range ground missile, sparking international concern not only about how China "weaponizing" space, but also about the debris from the satellite that is still floating around in space.

Beijing is also working on ways to jam satellite signals and is developing directed energy weapons, which emit energy towards a target without firing a projectile, Schulte said.

US concerns over China's space activities have led Defense Secretary Robert Gates to seek to include space in the stability dialogue with the Chinese, Schulte said.